An apparatus for controlling alcohol interlock includes a sensor that senses an environment of a driver's seat and a camera that obtains a face image of a passenger and an image of exhalation of the passenger. A controller activates a start lock mode of a vehicle and determines whether a condition for detecting components of the exhalation of the passenger is satisfied based on the environment of the driver's seat. The controller determines whether the exhalation of the passenger is exhalation of a driver based on the face image of the passenger and the image of the exhalation of the passenger, and determines whether to detect alcohol concentration in the exhalation of the passenger based on the determination result.